Negative network

From dermoscopedia

This chapter describes the histopathological correlation of negative networkSerpiginous interconnecting broadened hypopigmented lines that surround elongated and curvilinear globules. in dermoscopyThe examination of [skin lesions] with a 'dermatoscope'. This traditionally consists of a magnifier (typically x10), a non-polarised light source, a transparent plate and a liquid medium between the instrument and the skin, and allows inspection of skin lesions unobstructed by skin surface reflections. Modern dermatoscopes dispense with the use of liquid medium and instead use polarised light to cancel out skin surface reflections.

The “negativeThis glossary term has not yet been described.” of the pigmented networkThis glossary term has not yet been described. (also known as reverse or inverse network) consists of relatively lighter areas comprising the apparent grid of the network and relatively darker areas filling the apparent “holes”. The lighter grid lines tend to be serpiginous and the darker areas, when viewed in isolation, resemble elongated tubular or curved globulesThis glossary term has not yet been described.. Histopathologically, the negative network appears to correspond to thin elongated rete ridgesEpidermal extensions that project into the underlying dermis accompanied by large melanocyticThis glossary term has not yet been described. nests within a widened papillary dermis or to bridging of rete ridges. Although the negative network is highly specific for melanomaThis glossary term has not yet been described. (95% specific), especially for a melanoma arising in a nevus {{{authors}}}: {{{title}}}. {{{journala}}} {{{year}}};). PMID: [1]. , it can also be found in some Spitz neviThis glossary term has not yet been described. and rarely in other neviThis glossary term has not yet been described., such as congenital neviis a type of melanocytic nevus (or mole) found in infants at birth. This type of birthmark occurs in an estimated 1% of infants worldwide; it is located in the area of the head and neck 15% of the time. {{{authors}}}: {{{title}}}. {{{journala}}} {{{year}}};). PMID: [2]. . In congenital nevi, the negative pigmented network is usually diffuse and symmetrical in its distribution. In contrast, the negative pigmented network seen in melanoma is often focal and asymmetrically distributed.

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